121.80.102.0/25

Public

Class A — /25 prefix — 126 usable hosts

Network Address
121.80.102.0
Broadcast Address
121.80.102.127
Subnet Mask
255.255.255.128
Usable Hosts
126
First Usable IP
121.80.102.1
Last Usable IP
121.80.102.126
Total IPs
128
Prefix Length
/25

Network address — the base address of the block (121.80.102.0). All devices in this subnet share this prefix. Cannot be assigned to a host.

Broadcast address — packets sent to 121.80.102.127 are delivered to every device in the subnet. Also reserved — not assignable.

Usable hosts — the 126 addresses between those two that you can assign to servers, VMs, or interfaces.

Subnet mask255.255.255.128 is the dotted-decimal equivalent of /25. Older tools and Cisco configs use this format instead of CIDR slash notation.

Full Details

CIDR Notation 121.80.102.0/25
Network Address 121.80.102.0
Broadcast Address 121.80.102.127
Subnet Mask 255.255.255.128
Wildcard Mask 0.0.0.127
Prefix Length /25
IP Address Class Class A
Total IP Addresses 128
Usable Host Addresses 126
First Usable IP 121.80.102.1
Last Usable IP 121.80.102.126
Network (Hex) 0x79506600
Broadcast (Hex) 0x7950667F
Address Type Public / Globally Routable

Binary Representation

Network Address
01111001.01010000.01100110 01111001.01010000.01100110.00000000
Subnet Mask
11111111.11111111.11111111.10000000

The first 25 bits (1s in the mask) identify the network. The remaining 7 bits identify hosts within the network.

Split into Equal Subnets

Split 121.80.102.0/25 into 2 equal /26 subnets (62 usable hosts each).

# CIDR Network First Usable Last Usable Broadcast Hosts
1 121.80.102.0/26 121.80.102.0 121.80.102.1 121.80.102.62 121.80.102.63 62
2 121.80.102.64/26 121.80.102.64 121.80.102.65 121.80.102.126 121.80.102.127 62

IP Address Sample

Showing first 16 of 128 total IPs.

121.80.102.0 net
121.80.102.1
121.80.102.2
121.80.102.3
121.80.102.4
121.80.102.5
121.80.102.6
121.80.102.7
121.80.102.8
121.80.102.9
121.80.102.10
121.80.102.11
121.80.102.12
121.80.102.13
121.80.102.14
121.80.102.15
… 112 more IPs …

/25 Subnet Reference

Total IPs 128
Usable Hosts 126
Subnet Mask 255.255.255.128
Wildcard 0.0.0.127

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